A number of optical detection systems have been developed for use in qualitative and quantitative nucleic acid measurements. Many such systems involve the use of fluorescing agents (fluorescent probes, markers, labels, or dyes) in which the resulting signal intensities are generally proportional to the reaction products of polymerase chain reaction (PCR) amplification.
As an example, U.S. Pat. No. 5,928,907 describes a system for facilitating real-time fluorescence-based measurements of nucleic acid amplification products utilizing a lens co-axially disposed with a fiber optic cable for focusing a single color excitation beam into the volume of a sample. U.S. Pat. No. 6,144,448 describes a fluorescence detecting device including direct fiber optic connections between a single light source, container holder and single fluorescence detector.
U.S. Pat. No. 7,315,376 describes a sample holder provided together with an optical manifold having an excitation source, a photo receiver, or both, for each sample. U.S. Pat. No. 7,507,575 describes a data acquisition device and a detection device coupled to the data acquisition device. The detection device includes a plurality of removable optical modules and a rotating disk having a plurality of process chambers having a plurality of species that emit fluorescent light at different wavelengths. U.S. Pat. No. 8,137,616 describes a system for performing multi-color real time PCR, comprising a flexible real time PCR instrument and a specific composition or reaction mixture for performing multiplex PCR.
There remains a need for an improved system and device for facilitating polymerase chain reaction that allows for detection of stationary samples, reduced sample read time and optionally simultaneous reading of multiple light wavelengths, resulting in an increase in the speed with which amplification and quantification take place. There is a further need for instruments that include multiple light sources and detectors that occupy minimal space and require little or no ancillary instrumentation for facilitating light provision, fluorescence detection, or movement of samples to read different samples or fluorescent wavelengths. There is a need for instruments that do not rely on precise and/or complex alignments of reflective components such as mirrors, enclosures, beam splitters, dichrotic/dichroric filters, or microelectronic mirrors for light routing. There is also a need for instruments that facilitate PCR and detection without direct connection between a sample holder and fiber optic cable.